package com.wd.util;

import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

/**
 * @author long
 * @Create 2012-10-8 上午10:07:32
 * @QQ 108232706
 * @version 1.0
 * @description DESUtil
 */
public class DESUtil {

	private static final String PASSWORD_CRYPT_KEY = "lovewandian";
	private static final String DES = "DES";

	public static byte[] encrypt(byte[] src, byte[] key)
			throws Exception
	{
		SecureRandom sr = new SecureRandom();

		DESKeySpec dks = new DESKeySpec(key);

		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey securekey = keyFactory.generateSecret(dks);

		Cipher cipher = Cipher.getInstance("DES");

		cipher.init(1, securekey, sr);

		return cipher.doFinal(src);
	}

	public static byte[] decrypt(byte[] src, byte[] key)
			throws Exception
	{
		SecureRandom sr = new SecureRandom();

		DESKeySpec dks = new DESKeySpec(key);

		SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
		SecretKey securekey = keyFactory.generateSecret(dks);

		Cipher cipher = Cipher.getInstance("DES");

		cipher.init(2, securekey, sr);

		return cipher.doFinal(src);
	}

	public static final String decrypt(String data)
	{
		try
		{
			return new String(decrypt(hex2byte(data.getBytes()), "lovewandian".getBytes()));
		} catch (Exception localException) {
		}
		return null;
	}

	public static final String encrypt(String password)
	{
		try
		{
			return byte2hex(encrypt(password.getBytes(), "lovewandian".getBytes()));
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	public static String byte2hex(byte[] b)
	{
		String hs = "";
		String stmp = "";
		for (int n = 0; n < b.length; n++) {
			stmp = Integer.toHexString(b[n] & 0xFF);
			if (stmp.length() == 1)
				hs = hs + "0" + stmp;
			else
				hs = hs + stmp;
		}
		return hs.toUpperCase();
	}

	public static byte[] hex2byte(byte[] b) {
		if (b.length % 2 != 0)
			throw new IllegalArgumentException("长度不是偶数");
		byte[] b2 = new byte[b.length / 2];
		for (int n = 0; n < b.length; n += 2) {
			String item = new String(b, n, 2);
			b2[(n / 2)] = (byte) Integer.parseInt(item, 16);
		}
		return b2;
	}
}